GMC have developed a Self-Compacting concrete in compliance with the NHBC Guidance on the use of reinforcement to concrete toppings above non-load bearing beam and block floors, NHBC Issue 8 – 03/01/2018. The concrete is designed primarily as an RC28/35 10mm CIIB-S cement with a target slump flow of SF2 with the addition of a Superplasticizer, Steel Fibres or Polypropylene Macro or Micro Fibres or a Fibres combination.
HANDLING AND PLACING SELF-COMPACTING CONCRETE
The form-work built to contain the self-compacting concrete should be watertight so as to minimise the risk of leakage when the fresh concrete is placed. It should also be noted that the plastic membrane upon which the concrete will be placed should be flat and free from any potentially crack inducing creases. The specification allows a minimum slab depth of 75mm. However, 100mm depth is recommended.
The concrete should be finished by using a ‘Dapple Bar’. The concrete should be tapped and rippled with the Dapple Bar in two directions 90 degrees to each other.
Within an hour of the dappling a proprietary curing agent should be applied onto the surface on the concrete. It is recommended that two layers are applied ensuring that no areas are missed. Standard dosage is approximately 0.2 Lts per m²
NATIONAL BRITISH STANDARDS INSTITUTE
All GMC concretes are supplied in accordance with BS EN206 and BS 8500. GMC also have third party Quality Assurance accreditation with the British Standards Institute, no. KM566349
Other Self Compacting concretes can be designed to suit Customer Specifications other than that mentioned above.